1. Field of the Invention
The present invention relates to a grass mower.
2. State of the Art
It is known to mount a lawn mower handle to the deck or housing of a lawn mower in various ways which permit adjustment of the handle assembly about a pivotal axis. The handle assembly is generally quite long and extends substantially rearwardly beyond the mower housing. The handle assembly generally comprises a lower frame including a pair of arms which are substantially parallel to each other and have one end secured to the housing and a generally U-shaped upper frame including a pair of free arms substantially parallel to each other and a closed end which is operated by the user to push the lawn mower along the ground. The distance between the two arms and the two free arms is substantially equal. During use, each arm of the lower frame is fixed to each free arm of the upper frame by a locking arrangement such as a bolt and nut. The locking arrangement can be manually released and the upper frame can be pivoted relative to the lower frame until the upper frame is substantially folded over the lower frame to allow the lower frame to be pivoted with respect to the housing until the lower frame overlies the housing for storage.
U.S. Pat. Nos. 3,527,469 and 5,636,504 disclose such a folded handle assembly including two means for respectively locking the side arms of the lower frame and the upper frame in its normal operational position. If only one side arm is locked, the handle assembly would twist when the operator pushed it because the unlocked handle arm could rotate with respect to the locked handle arm. However, it is an inconvenient and time consuming activity to lock both of the arms of the frames of the handle assembly. In addition, there is a risk that an operator will forget that both arms need to be unlocked before the handle assembly can be folded.
Moreover when it comes to adjusting the operating height of the handle assembly relative to the housing, the operator has to unlock both lower arms from the mower deck, pivot the handle assembly relative to the mower deck and lock the lower arms on the mower deck at the desired operating position. The connection between arm ends and mower deck is generally complex which makes the adjustment inconvenient.